"Did you hear that?" Derek glanced into the shadows of the next aisle as they walked between the towering metal shelves, each piled with treasures from history from across time and distance, numbered and neatly stored. "I could swear there's something over there, professor."

"It's nothing," the older man said, only half-listening as he searched for the right shelf and bin number. "Keep looking. We have to find the right case before we can verify the providence of the piece."

A shadow darted through the empty space in front of them, across the windows, silhouetted for the briefest of moments.

"Professor," Derek began, but the other man wasn't listening, pulling a moving ladder over to a shelf.

"Here it is! I'll reach it down to you," he said as he began to climb, raising him arms over head to catch the handle of a heavy wooden box. Using both hands to steady the container, he started to reach it down. "Derek? Where are you? Grab the end of …."

The box fell with a crash as the professor saw the blood spattered from Derek's body, still convulsing, his eyes slowly fading. Packing straw spilled out, soaking up the spreading puddle as the professor stumbled down the stairs, dropping to his knees. He looked up as the shadow blotted out the overhead light, red fangs and hands covered with gore poised above his head.

And then they ripped his heart from his chest.

Sam was amazed that they made it as far as they did with their fake badges. He'd told Dean the plan wouldn't work; it took an amazing amount of hubris to pretend to be agents when they were just blocks away from the F.B.I. Headquarters in D. C. But they'd gotten into the building, down the stairs and were now standing mingled among employees, within sight of the crime scene tape and the black suited agents and lab techs in white coveralls. At least Dean hadn't tried to bluff their way into a group of what were obviously government types; they'd have to make do with what they could hear now and conduct interviews later.

A woman brushed past him and ducked under the yellow tape; Sam's first thought was that she had a really nice ass showcased in her snug jeans, slung low on her curvy hips, tucked neatly into brown low heeled boots. The soft blue cotton of her Led Zeppelin concert shirt clung to her breasts, framed by a brown bomber jacket, the real deal pilots wore, not one of the fake coats anyone could buy. Her blue eyes were intense, blonde hair tied back, little red gems hanging from her earlobes.

"Who the hell is that?" Dean asked. Sam shrugged; it was obvious she was expected as one of the dark suited men met her, nodding as she stepped closer to observe the scene. "She's not a fed, that's for sure."

Her eyes surveyed the tableau of death, two bodies piled one on top of the other, and then turned to check the rest of the room, circling slowly until her gaze passed over the onlookers, returned, and settled on the Winchesters with a glint of recognition. Tilting her head to the agent, she spoke and motioned towards them.

"Ah, shit, I think we've been made." Dean started to fade back into the group, easing towards the door. Hiding in the crowd was easier said than done for two men as tall as they were, but both had learned the art of looking normal and unassuming.

"Dean and Sam Winchester?" Amazing how a name could make people notice you; the others stepped aside, leaving them exposed to the agent. "Ms. Danvers said your expertise will be welcome. If you'd join us?"

Sam threw Dean the question, one eyebrow raised; his brother gave him the shoulder wiggle that meant, "what the hell, why not?" Following, they crossed the space to where the blonde waited.

"Sam," she held her hand out to him without hesitation; Sam slid his hand in hers for a moment, their blue eyes meeting, hers filled with humor. "Dean." She did the same for his brother, a brisk shake and slight smile, looking a little longer as if sizing Dean up. "Carol Danvers. We could use your take. This might just be in your area of expertise."

"What happened?" Dean asked, putting off the inevitable question of who she was in favor of the case in front of them.

"April, this is Dean and Sam Winchester. They're working with me," Carol said to the woman who was kneeling by the bodies. "Can you bring us up to speed?"

"Professor Allen Markowitz, age 45, and Derek Shields, 27. They were here on a fellowship, working on some historical research, Civil War family genealogy or something like that." The woman stood up; she wore the unofficial uniform of police detectives everywhere: off-the-rack suit, white button-up shirt, slightly rumpled. She'd added a paisley scarf to try to add some personal style. "They signed in at 3:43 p.m. yesterday … all visitors have to … and then never signed out. One of the janitorial staff found them at 5:56 a.m. this morning. The last person to see them was another researcher, one Dr. Robert Gordon, as he was leaving at 7 o'clock last night. They spoke, talked about meeting for lunch today."

"Any idea on time of death?" Carol asked.

"The coroner will have an estimate later," the detective replied. "But we can say whoever did this would draw a lot of attention to themselves. They'd have been covered in blood. Both men had their throats ripped down to their spinal cords."

As they were talking, Sam wandered over to the shelves, noting the position of the ladder and the shattered wooden box on the floor. Slipping his phone out of his pocket, he snapped some quick pictures.

"This is going to sound strange, but are their hearts missing?" Dean asked; April seemed surprised, but Carol only nodded, as if expecting the question.

"Why, yes. That's the weird part of all this. Four bodies, completely different circumstances, but all with no hearts. The brass thinks we might have a pattern. That's why they asked the F.B.I. for support."

"Four?" Dean's question was sharp and focused.

"Found the first six days ago. A garage mechanic out in Arlington. Looked like a robbery gone bad; he ended up smashed under a Suburban. Took the M.E.'s office four days to piece him together. Then a jogger in Rock Creek Park; theory was she fell and animals got to her body. She was found three days ago, but died first, probably two weeks earlier."

Dean's look to Sam said it all. Werewolves, no doubt.

"Excuse me, but do we know what Professor Markowitz was looking for down here?" Sam bent to look at the shattered pieces of bone china that spilled across the floor. Half of a hand painted teapot sat in a circle of dried blood, roses covered in red specks.

"No, but we can ask the Head Archivist. He's next on my list," Carol gave April a pat on the shoulder. "Let me know any new developments, okay, Sherlock?" The two women shared a laugh.

"Same for you, Marvel. You, I trust. The feds? Not so much." She turned back to the techs.

Dean managed to make it to the stairwell, out of view and earshot of the others before he caught the woman's arm and brought them to a halt. Sam was only surprised it had taken Dean this long; his brother didn't like being out of the loop, and Carol obviously knew who they were.

"Alright, that's far enough. Who exactly are you, and what's going on?" he demanded.

She shook off his hand easily. "Lt. Carol Danvers. I work with Clint Barton. He said you might show up here." Her smile was genuine. "Been looking forward to meeting you. The Hawk speaks highly of you."

Dean got that look – the one he had whenever Clint's name surfaced in conversation - and Sam's couldn't help but grin at the sight of his brother's flustered face.

"So you're with SHIELD?" Sam asked. Carol turned her full attention to him; there was something about her gaze, the way she really looked at him. Oh, she checked him over from head to toe, a definite spark of interest in her eyes when she was done, and Sam's cock stirred at the thought of that intensity channeled into other pursuits. He returned her smile with one of his own, ignoring Dean's eye roll at the silent exchange.

"Sort of. I'm more of a … consultant … I specialize in enforcement and justice, I guess you could say."

Sam's eyes narrowed at the explanation which didn't clarify anything. "So you don't work for SHIELD?"

Carol only winked and turned to Dean. "Your brother's not the trusting type, I take it."

"He's coming off a problematic relationship," Dean offered with a shit-eating grin. "He's off of women at the moment."

"Fine," Sam knew he'd been outflanked. "We need to check those other two victims, visit the scenes, and see if the Head of this place knows anything."

. . . . . . . .

"So Abigail Adams had Hera's bowl, kept her pins in it, and that's what you think they're after? How does that connect to the tea set Professor Markowitz was looking for?" Carol walked out of the building with them, pulling up information on her notebook tablet, watching the brothers as they worked through the problem in front of them. Clint had talked about the two hunters with admiration – and that was saying a lot if Clint trusted them. But even more interesting had been what Clint didn't do; he'd described Sam, the way the two worked as a unit, even their silent communication skills, but he didn't talk much about Dean other than to say that the man was damn handy in a fight and that he liked rock music. He'd neglected to mention how their file photos didn't do them justice, how Sam's boyish handsomeness showed beneath his outward strength. And of Dean's model good looks, well, Clint had been mysteriously quiet. Carol thought she knew exactly what that meant.

"These items tend to pass down through families or into the hands of people who fit a certain profile. Abigail was a strong woman, wife of one president, mother of another. Makes sense the bowl would find its way into another powerful family." Carol had to admit the two were good investigators, falling easily into the flow of good cop/bad cop even with a new element – her – in the mix. And Dean could glower his fill; it didn't bother her one bit. Now, Sam … yeah he could look at her with those puppy dog eyes all he wanted. THAT didn't bother her either.

"We can't assume the teapot had anything to do with it; they could have been in the wrong place at the wrong time." Dean offered, obviously relishing his role as devil's advocate or just being obstinate, Carol couldn't tell which. "We need a complete listing of what's in that area of the building."

"You saw the way he looked when you demanded that." Sam argued with his brother. "He's not going to hand that info over."

"Here." Carol reached forward and showed Sam her notebook where a long list of items scrolled on the screen. "It's a massive amount to comb through. I'll get Jarvis on it right away. Maybe we can pare it down with some specific parameters. Important families, strong women." Her fingers flew over the screen, entering data, and the list began to narrow.

"Cool toys." Dean muttered. "Got any exploding arrows?"

"Don't need them," she said, smugly. "Clint's the one who has his toys." From Dean's abrupt silence, she knew she'd hit her target. Oh, god, she was going to get so much mileage from this little bit of knowledge. She'd make Clint do her paperwork for a good month in exchange for her silence. Or KP duty. Yeah, she hated doing dishes.

"I think it's worth checking out the mechanic and the jogger. See if we can build a pattern. Garage first?" Dean said, changing the topic, and Carol let him, catching Sam's eye and winking. They turned the corner and Carol came to an abrupt stop. The black car sat at the curb, parked illegally, slick finish shining in the late afternoon sun as Dean walked around to the driver's side.

"Is this your car?" She stepped up to the Impala, running a hand along the curve of the trunk. There was nothing better than a classic muscle car in prime condition … except maybe a classic muscle car in prime condition driven by two sexy men. "Damn, boys. This is one fine ride. '69?"

"'67," Dean practically beamed with pride at her reverent tone.

"We are so taking this baby." With a wicked grin, she leaned against the shiny black finish. "What do I have to do to get the keys? I promise I'll be careful with her." She pretty much meant it too; she'd give anything to turn this lover over and feel the way it handled.

"Sorry," Dean opened the driver's door. "But Sam will let you ride in the front seat, right?"

"Sure," Sam opened the door for her. As she slid in, she knew she'd find some way to get behind the wheel of this wet dream of a car. It was just a matter of finding the right leverage.

. . . . . . . . . . .

The Point Auto Shop was open when they drove into the lot, three of the four bays filled with cars in various stages of repair; men were working, but the last bay stood empty, even though there were cars lined up along the side of the building. As they rumbled to a stop, an older black man exited the office, tablet pc in his grease stained hands; he altered his path when he got a good look at the Impala.

"Nice car!" he called. The nametag proclaimed he was Mac. "How can I help you?"

"FBI. We'd like to ask you some questions about the death of Walter Emmerts." Dean flashed his fake badge, knowing Sam would follow his lead. Who the hell knew what Danvers would do? Clint's 'friend' had been helpful – Dean would admit that much – but her needling was getting on his nerves. Sam was bad enough with that damn picture he kept on his phone, but now this unknown woman kept bringing up the agent Dean was trying to forget. Okay, she had good taste in cars, but that wasn't enough.

"I already told the police everything I know, which isn't much," Mac brushed his hand along his coveralls; a sadness filled his eyes at the mention of the dead man.

"If you could go through it again, we'd appreciate it," Sam said, pulling his phone from his pocket to take notes. Out of the corner of his eye, Dean saw Carol wander in the direction of the empty bay; she scanned the ground as she went in the way that a good investigator did, watching for anything out of the ordinary.

"Well, Walt was working late, fixing Sal Johnson's Camaro – that's another nice classic car, even if Sal pimps it up too much and rides the clutch too hard, which was what Walt was working on – anyway, I left about 7:00ish, my granddaughter had a band concert, not that kids that age do more than blow into their instruments and make noise, but she loves it when her Papaw shows up, so I had to get out of here early, before closing, to make the drive all the way up to Gaithersburg. Said goodbye, made sure things were going okay – he was almost finished, said he'd be done in an hour or less, cause he wanted to go meet his girl for a late dinner. That was it. Next thing was the phone call from the police; someone saw the light still on and stopped in – their mini-van was rattling and they were worried about it stopping on the road home – and they found him. Or what was left of him."

Throughout the man's long rambling speech, Dean surveyed the area; the street was fairly busy, but the building turned sideways, so the bay where the man had died was on the furthest end, half-hidden. Clean and tidy, the business looked prosperous, and Mac seemed genuinely torn up about Walter. All told, it seemed like a normal shop in a busy suburban area. Except for a smashed body missing its heart under an SUV.

"Did Walt have any enemies?" Sam followed up. Dean had lost sight of Carol; she'd entered the building and hadn't come out yet. He had the itch to follow her, to see if she found anything. Clint might be someone he could trust, but he hardly knew this Carol woman – and saying she was a friend of a friend didn't quite cut It for Dean.

"Nah, he was a great guy. Hard worker. Learned everything he knew in the service – he was a mechanic for the Army, did two tours in Afghanistan, could keep any vehicle running with spit and twine. A real MacGyver type, if you know what I mean. Sure, he had a little trouble adjusting to coming home – so many of them do, you know – but he never missed work, never even late. Just an occasional few days off."

"And the girlfriend? Any family?"

"Just a step-sister, out west somewhere …. Harry!" he shouted back into the office. "Where was Walt's sister living again?"

"Nevada," came the answering shout.

"Nevada. And the girl was Mary Andrews. Worked down at the Starbucks in the metro station. Going to school to be a psychiatrist or a psychologist or one of those mental doctor types. Good kid."

Dean saw Carol emerge and squat down near the floor of the garage; he crossed the lot and looked over her shoulder at the red stains still evident on the concrete.

"They dropped the car on him while he was standing under it, according to the report," she started talking as she stood up. "The control is over there by the workbench, pretty long way away, so you've got ask yourself why was still under the car. Even with a gun on you, I'd take the chance to dive out of the way. He didn't. But here's the strange part." She turned the small device in her hand to show Dean a graph that made no sense to him at all, but he didn't want to admit it, so he just nodded. She tucked the analyzer back in her pocket. "High level of an unknown anti-body in his blood stream. The lab's going to start working on identifying it right away. Something was going on at a genetic level in his body."

"Anti-bodies?" Sam asked from behind them. He and Mac had followed them over; Carol stood and held her hand out to the older man.

"Carol Danvers. I work with SHIELD." With a firm handshake, she smiled at the owner.

"SHIELD? Since when do you work with FBI? If I remember, Fury hates all the other agencies." Mac laughed as he looked Carol up and down. "Bet these two aren't really FBI. His hair's way too long to be regulation."

"You ex?" Carol asked.

"Until a HYDRA blast in '02. Got out and started this place."

Dean watched the two of them fall into an easy discussion of the murder, thick as thieves; he'd noticed the way she said she'd worked with SHIELD, not for them. An important distinction, but he didn't know why just yet. Whatever SHIELD did, membership, even those retired, seemed to mean automatic insider status.

"Told you the hair was a dead giveaway," he muttered to Sam.

"Yeah, and the car is standard issue? Give me a break," Sam shot back. At least they knew they'd gotten all they could from the owner now that he was Carol's best friend.

, , , , ,

It was growing dark by the time he reached the specific spot in Rock Creek Park where the jogger had died. Police tape still hung limply from one of the trees, but the area had already been cleared out and left to the elements. Squatting down, Dean looked at the ground, hoping to find some insight as to what had happened, but there was little left to see. He glanced around for Sam and Carol – they were sweeping the path in either direction, looking for any clues – but they were out of sight. A branch cracked off to his left, further back into the thicket; he drew his gun just as two men stepped out of the shadow of the trees, their own weapons leveled at him.

"Wrong kind of shoes for hiking," Dean quipped; both of them wore shit kicker biker boots, worn and scuffed, with their jeans and jackets. "So I guess you're not joggers either." He waited for them to speak, to issue some sort of threat, but they remained silent. "Umm, this is where you call me some creative name and tell me I have to come quietly. Haven't you been to thug school yet?"

Their eyes glinted silver, canines elongated as they smiled. "Nah," said the one on the left. "Don't have to do anything. He'll take care of it all."

A muscular arm whipped around Dean's chest and a hand pressed an injector against his neck; with a hiss, tranquilizer flooded his system, the world spiraled out of control, and the earth came up to meet him.

. . . . . . . .

"Where the hell did he go?" Sam fumed. "We were only gone a few minutes."

Carol dropped down and put her hand on the ground. "Someone took him. Three men I think, but not quite human."

"What?" Sam was torn between being angry at Dean for wandering off or being scared that something had happened to his brother, and either way, he wasn't in the mood to be civil to this woman who appeared to just pull information out of the air.

"The more recent the event, the easier it is," she was distracted and didn't pay attention to Sam's reaction. Some sort of sixth sense or something? Sam was incredulous. Great. He needed to find Dean, not deal with this. "He was alive, that's for sure."

"Look, it's not like I don't believe in psychics … I've known a few real ones in my life, but only a few … excuse me this just stretches belief." Sam ran a hand through his hair, frustrated by the turn of events. If Dean had run off on some wild hair, he was going to read him the riot act when he got back. But the Impala was still in its parking spot, and Sam's gut said that Carol was probably right – Dean was missing.

"There's a lot you don't know about me, but none of this is helping your brother." Carol gave him a hard look as she pulled her phone out of her jeans pocket. "You don't have to trust or even believe me, but Clint will kill me, creatively, if I let anything happen to Dean on my watch." Before someone could answer her call, she lowered the phone, and Sam could tell that her senses were on alert, surveying the woods around them. "They're coming, at least two of them, from the …."

Two men burst out of the low growth shrubs, launching themselves at Sam and Carol. Eyes glowing silver, claws instead of fingernails, long canines – the werewolves were on them fast; Sam had time to dodge to the side and draw his knife, but the werewolf's claws caught his shoulder, ripping through his outer coat and shirt, drawing blood. Slashing under hand, Sam swung the sharpened silver edge at the man's stomach, but he danced backwards, a wide-mouthed grin on his face.

"Got to do better than that, boyo," he taunted, moving with the speed and grace of a martial artist as he threw a roundhouse punch which connected to Sam's chin, knocking him three steps back. "Heard you were big bad hunters, you and your brother. Not so impressive, I have to say."

Sam shook his head to clear it from the last blow. "Yeah, well, I've taken down bigger monsters than you." He feinted to the left, and then drove to the right, catching the werewolf's arm with his blade; the man jumped at the touch of silver on his skin.

"I'm not playing with you, kid. Orders are to put you down." Punches followed, quickly, a style of fighting that had Sam pushed back into a tree trunk in short order. He could barely deflect the powerful strikes, much less worry about Carol; this was the strongest damn werewolf he'd ever met, and the man had serious training and skills.

"What the hell have you done with my brother?" Sam growled when the man pinned him against the tree with his forearm, palming his knife for a last ditch effort to take the werewolf out.

"Count yourself lucky. He's in for much worse."

The werewolf drew his hand back for a killing blow when a bright bolt of light slammed into his back, and he arched his frame, mouth opening in a scream of pain. Sam drove the knife home, into the heart, and the man's eyes widened in surprise at his death, dropping to his knees and falling on his side

Carol floated a few feet away, hands outstretched, second werewolf on the ground at her feet. Sam blinked. Carol was floating, literally, feet off the ground.

"What the…" Sam started to ask, but the other werewolf made a last ditch leap at Carol, surging up towards her. She spun, effortlessly, flying a little higher, two quick bolts blasting from her hands at the man, knocking him back down.

"What keeps them down?" She asked Sam; for a second, he could only stand and look at the flying woman, but then years of hunter experience of the weird and supernatural kicked in and he tossed her the knife.

"Silver. In the heart." She landed and dispatched the twitching figure quickly.

"So," she said after a few heartbeats of looking at Sam's incredulous face. "Guess Clint didn't exactly fill you in on the team, I take it?"

Sam shook his head no.

"Well, then, let's try this again." She held her hand out to Sam. "Hi. I'm Carol Danvers, also known as Ms. Marvel. Nice to meet you."

The picture snapped into focus for Sam, all the little things he'd missed suddenly making sense. "You're one of the Avengers." Carol nodded. "And Clint? You called him Hawk. He's Hawkeye." Another nod. "Oh, god. Clint talked about Tony … that would be Tony Stark?" One more affirmation from Carol. "The freakin' Avengers." Sam felt the grin spread across his face. "Dean's going to shit a brick when he finds out. Probably get really pissed at Clint."

"I'll love a front row seat to that little discussion," Carol said. "But first we have to find him."

That sobered Sam up quick; the grin disappeared, and it was his turn to nod. There was not time to think about flying superheroes. Dean was out there, and, if the werewolf had been telling the truth, he was in serious trouble.